Tangent screw adjustment for pivoted calipers



y 1950 A. E. BERNARD 2,514,024

TANGENT SCREW ADJKjSTMENT FOR PIVOTED CALIPERS Filed Ocfi. so, 1944 2 Sheecs-Sheet 1 2/ 2/!L /5 y 9 A Inventor WW 15 M Patented July 4, 1950 UNITED TANGENT SCREW ADJUSTMENT For. PIVOTED CALIPERS Andrew E. Bernard, Cleveland, Ohio Application October 30, 1944, Serial No. 561,016

1 Claim. 1

This invention relates to precision-type calipers, and has more specific reference to a calipering instrument characterized on the one hand by novel and improved manually manipulated mechanical spreader means, whereby to provide a highly satisfactory tool for measuring the internal diameters of bores, sockets, and the like.

One phase of the invention has to do with novel means coacting with the hingedly adjoined ends of the frame sections, said means being precision made and serving, with requisite nicety, to open and close said frame sections slowly and with accuracy to thus effectively control the usual type work-engaging feelers.

More specifically, and in reducing a preferred embodiment to practice, a novel frame is provided and said frame is made up of a pair of complemental sections or units and corresponding inner end portions of the sections are expressly designed for coaction with each other and are hingedly connected together. The hinged end portion of one section is formed with a segmental worm gear while the coacting hinged end portion of the remaining section is slotted. A pivotally mounted and rotatable worm element is carried by the last namedsection and is operable in the slot and is in mesh with the worm gear and said worm element has a knurled finger-grip with the finger-grip projecting beyond the slot and being located for operation between the hingedly connected end portions of the respective sections, suitable means being provided to releasably hold the worm element against the teeth of the worm gear, said means being such as to permit the worm element to be disengaged from the worm gear whenever the user desires to freely move the frame sections toward or from each other.

Other features and advantages will become more readily apparent from the following de scription and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Figure 1 is a View, partly in section and partly in elevation, showing a caliper, in one of its forms, this characterized by one type of adjusting device and a conventional dial indicator.

Figure 2 is a perspective view of the adapter for said indicator.

Figure 3 is a detail section on the plane of the line 33 of Figure 1.

Figure 4 is a further detail cross-sectional view on line 44 of Figure 1.

Figure 5 is a view similar to Figure 1, showing a modified type of caliper equipped with a conventional dial indicator;

Figure 6 is a topplan view of Figure 5, with the dial indicator removed. v

Figures '7 and 8 are detail sections on the planes of the lines ll and 8+8, respectively, of Figure 5. I

The invention is illustrated as exemplified in two forms or modifications, for which reason attention is directed first to the structural arrangement depicted I'm-Figures 1 to 4, inclusive. To this end it will be seen thatthe aforementioned sectional frame is characterized by a pair of complemental suitably curved and otherwise shaped and proportioned companion sections 5 and ill, respectively. The unit 9 comprises a substantially C-shaped portion H formed, as at 2, with a segmental worm gear (see Fig. 3). The opposite end is fashioned into an arm [3 carrying a feeler I 4 detachably mounted at l5. The remaining unit IE] is of somewhat the same general outline or configuration, and comprises a substantially Q-shaped complement it provided with a chambered portion ll terminating in extensions or furcations l8 which straddle the worm gear l2 and are pivotally connected thereto by an assembling and pivot stud [9 having a binding and clamping nut 25) on the threaded end. Pivoted in the cavity or chamber ll is a worm screw 2! held in mesh with the gear teeth by a pivoted friction shoe '22 having a beveled edge (see Fig. 3) with which a set screw 23 coacts. The purpose of the set screw is to force the block or shoe .22 against the worm, and the worm against the gear, to maintain the parts 9 and If! in the relationship seen in Figure 1. Consequently, by turning the thumb wheel 24 on the rotatable worm, the parts 9 and Ill can be graduallyspread apart or brought together. This is for manually regulated, fine mechanical ad justments. By releasing the set screw 23 and also releasing the friction shoe 22, the worm 2! can be disengaged from the gear to throw out the regulating mechanism and to permit the units 9 and I!) to be opened and closed independently thereof, this for quick hand adjustment. In connection with the construction of the worm 28 it is to be pointed out that this particular part 2! is hollow in construction and fits like a sleeve over the coacting pin 21a. The pin, in turn, is hingedly mounted as at 2lb and is provided at its outer end with an endless groove forming a keyway 2 lo. Thus, by providing the worm sleeve 29 with a set-screw 24a, the set screw fits into the groove and provides the assembling and swivel inner end of the shank is provided with a tapered projection or actuator 29 engaging the reciprocatory stem 39 on a conventional type dialindi cator 3|. The sleeve or neck portion 32 of the indicator is mounted in a collar 33 on-th'e outer end of an adapter arm 34 which fits into a socketin the curvate portion of the part 16. This arm is held assembled by a set screw 35. In addition, a set screw 36 is provided in the adapter collar for swivelly mounting the dial 3|. The dial can be switched in any direction for convenient reading purposes. It is obvious that thestem of the dial is operated by the swinging or pivoting motion of the feeler Ma whichis translated through the lever-like shank 21 to said stem.

The same fundamental ideas are carried out in a difierent form in the embodiment of the invention seen in Figures 5 to 8, inclusive. Here the frame unit 9a is provided with a curvate or C-shaped portion Ila having an -arm-l3a on which the feeler I4 is detachably mounted, as at l5. As shown in Figure 7, the hinged end portion of the part I la is provided with spaced parallel extensions 31. A stub axle 38 is journaled in a bearing and provided with a thumb-wheel 39 and a pinion 40. The pinion 40 coacts with a segmental gear 4| forming a part of the body portion [6a. This'terminates in spaced parallel end extensions ll which receive between themselves the aforementioned extensions 31. This provides the desired hinge jointingconnection between the two-units 9c. and was A headed hinge'pin'43 (see Fig.7) extends through the extensions 31,- M- and 42, thus connectingthe two parts 9a and lfla-together. The threaded end of said pin is provided with a knurled binding wheel 44, this for purposes of maintaining the adjustment obtained through the intermeshing gears 40 and M. It is evident that by turning the wheel 39, the gears serve to move. the parts 9a and Illa toward-and fromeach other for evident adjustment purposes. 'When the adjustment is obtained, the wheel 44- is tightened to bind the hinge and to thus lock the parts in the positions to which they have been thus adjusted. It is necessary to loosen the wheel 44 to make the initial adjustment and then tighten it to retain the adjustment, as is obvious.-

The feeler Ma is the same as that shown and described in Figure-1 and the same reference numerals are employed to designate corresponding parts. In this instance, however, the indicator gauge is also. a horizontal standard-type dial indicator. 7 This is denoted by the numeral 45, its stem. 46 engagingthe actuator 29. The attachment shank 41 is fitted in an adapter socket 48 and held in place by a set screw 49.

As stated, these types of calipers are used. for internal bores or slots or. anyinternal work.

4 They serve to permit standard horizontal and vertical, as well as swivel-type, dial indicators to be employed in conjunction therewith. The tool as constructed need not depend on skill of the user to obtain accurate reading. The range of measurements is greater than in other similar types of measuring calipers. The forms of the invention herein shown are inexpensive, practicable and aptly fitted for the purposes intended. In brief, we have a novel caliper equipped with a dial gauge and actuating means for the. gauge in the form of pivoted feelers. Further, the adjustment devices, hand regulated and as disclosed in both embodiments are advantageous and appropriate for the purposes intended.

A careful consideration of the foregoing description in conjunction with the invention as illustrated in the drawings will enable the reader to obtain a clear understanding and impression of the alleged features of merit and novelty sufficient to clarify the construction of the invention as hereinafterclaimed.

Minor changes inshape, size, materials and rearrangement of parts may be resorted to in actual practice so long as no departure is made from the invention as claimed. I

I claim:

A pair of calipers comprising a frame, said frame embodying a pair of substantially duplicate units, corresponding inner end portions of said units being adjustably and hingedly connected together, the hinged portion of one of said units being formed with a segmental worm gear, the coacting hinged end portion of the remaining unit being slotted, a pivotally mounted and rotatable worm element carried by the lastnamed unit and operable in said slot and being in mesh with said worm gear, said worm element having a knurled finger grip and said finger grip projecting beyond the slot and being located for operation between the hingedly connected end portions of the respective units, a friction shoe pivotally mounted in the last named unit and in frictional contact with the worm elementand' serving to hold the latter against the worm gear orto be releasedand. bodily swung and disengaged from theworm gear,- and a set screw on the last-named unit engageable with said'shoe to. press the shoeinto place or to release it in relation to theworm element, as desired.

1 ANDREW BERNARD.

REFERENCES CITED The following references are otrecord-inthe file of this patent:

UNITED STATES PATENTS Number Name Date D. 135,757 Nelson June 1, 1943 279,534 Byrne June 19, 1883 296,259 White Apr. 1, 1884 499,053 Strand June 6, 1893 613,814 Benes, Nov. 8, 1898 1,269,336 Taylor June 11, 1918 1,274,331 Rockwell July 30, 1918 1,305,701 Douglass June 3, 1919 1,324,870 Zito Dec. 16, 1919 1,876,280 Dunn Sept. 6, 1932 

